/*
 * Copyright (c) Huawei Technologies Co., Ltd. 2025. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package utils

import (
	"bufio"
	"fmt"
	"os"
	"strings"
)

// Memory -
type Memory struct {
	MemTotal uint64
	MemFree  uint64
}

// ReadMemoryStats - returns memory info from /proc/meminfo
func ReadMemoryStats() (*Memory, error) {
	file, err := os.Open("/proc/meminfo")
	if err != nil {
		return nil, err
	}
	defer file.Close()

	scanner := bufio.NewScanner(file)
	var totalMem, freeMem uint64
	for scanner.Scan() {
		line := scanner.Text()
		if strings.HasPrefix(line, "MemTotal") {
			_, err := fmt.Sscanf(line, "MemTotal: %d kB", &totalMem)
			if err != nil {
				return nil, err
			}
		}
		if strings.HasPrefix(line, "MemFree") {
			_, err := fmt.Sscanf(line, "MemFree: %d kB", &freeMem)
			if err != nil {
				return nil, err
			}
		}
	}

	if totalMem+freeMem == 0 {
		return nil, fmt.Errorf("failed to read any memory info at %s", file.Name())
	}

	return &Memory{
		MemTotal: totalMem,
		MemFree:  freeMem,
	}, nil
}
